Scraping blade assembly

ABSTRACT

A scraping blade assembly includes a pair of elongated scraping blade members and a blade supporting and mounting means having a pair of walls with a space therebetween. The blades are mounted within the space and a transverse bar member extends through apertures in the walls and the blades to loosely mount the blades within the space. The apertures in the blades are offset from the midpoint thereof so that the blades will gravitationally tilt under their own weight, to assume a position wherein a dihedral angle is formed between the scraping edges of the adjacent blades.

taes [191 Whitsett 1*Feb. 12, 1974 I SCRAPllNG BLADE ASSEMBLY [76] Inventor: Jack W. Whitsett, 936 Castile Ave.,

Coral Gables, Fla. 33134 Notice: The portion of the term of this patent subsequent to May 16, 1999, has been disclaimed.

[22] Filed: May 4, 11972 [21] Appl. No.: 250,188

[52] US. Cl. 15/236 NO, 15/242 [51] llnt. Cl A471 13/02 [58] Field of Search 15/242, 243; 175/263, 265,

[ 5 6] References .Cited UNITED STATES PATENTS 2,193,721 3/1940 Gunderson 175/263 3,662,424 5/1972 Whitsett 15/236 R 1,022,129 4/1912 Evans et al. 175/263 FOREIGN PATENTS OR APPLICATIONS 987,666 4/1951 France 175/263 Primary Examiner-Leon G. Machlin Attorney, Agent, or Firm-Roylance, Abrams, Berdo & Kaul [5 7] ABSTRACT A scraping blade assembly includes a pair of elongated scraping blade members and a blade supporting and mounting means having a pair of walls with a space therebetween. The blades are mounted within the space and a transverse bar member extends through apertures in the walls and the blades to loosely mount the blades within the space. The apertures in the blades are offset from the midpoint thereof so that the blades will gravitationally tilt under their own weight,

to assume a position wherein a dihedral angle is formed between the scraping edges of the adjacent blades. 1

7 Claims, 2 Drawing Figures Patented Feb. 12, 1974 3,790,983

20L if v 30L scnAPiNG BLADE ASSEMBLY This invention relates to a scraping blade assembly and in particular it relates to a scraping blade assembly which finds particular utility when used in a sraping device such as that defined in my copending application Ser. No. 60,344, now U.S. Pat. No. 3,662,424 issued on May 16, 1972. i

In the aforementioned copending application, there is described as scraping device which can be operated from a drive means, such as a power drill, to set a pair of blades into circular rotation so that they can perform any desired scraping function, such as scraping a wall to remove paint therefrom, scraping a metallic surface to remove rust or scale therefrom, and the like.

As described in the aforementioned copending application, the disclosure of which is hereby incorporated by reference, when a scraping device includes a pair of blades which are ordinarily disposed at a dihedral angle, but which, when the device is operated, assume a coplanar relationship, certain inherent and important aspects and advantages are present. That is,gyroscopic principles of inertia and precession are present when the blades are rotated at a high speed, and these forces cause the blades to resist the effect of any surface pressure which would tend to push the blades out of their planar and scraping relationship.

lt is an object of the present invention to provide a scraping blade assembly which can be sold as a unit and which is particularly useful in a scraping device such as that described in the aforementioned copending application.

lt is another object of the present invention to provide an improved scraping blade assembly wherein the blades are maintained in their proper initial relationship but wherein they are movable during operation of the scraping device to assume the desired coplanar relationship.

Another object of the present invention is to provide a scraping blade assembly which can be marketed as a single unit, but wherein the assembly can be taken apart to permit repair or replacement of the blades.

Another object of the present invention is to provide a scraping blade assembly which is simple and efficient in its construction, yet which is capable of permitting extended periods of operation in a scraping function without the need for any undue maintenance.

Another object of the present invention is to provide a scraping blade assembly which maintains the scraping blades in their desired positions, both while the device is performing its scraping function and while the device is stationary.

Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment thereof.

The foregoing objects are attained by providing a blade supporting and mounting means which includes a pair of spaced walls having transverse aligned apertures therethrough and a bridge member interconnecting the walls. The space. between the walls define a blade receiving member into which a pair of scraping blades can be inserted. The scraping blades have transverse apertures formed therein, with each aperture being offset from the midpoint of the blade to thus provide a longer section to one side of the aperture and a shorter section to the other side thereof. Within the blade receiving space, the blades are aligned so that the shorter section on one blade is adjacent the longer section on the other blade, and vice versa. A rod member projects through the apertures in the walls and the scraping blades to thus rotationally mount the blades to the blade supporting and mounting means. The upper edges of the blades abut against the side edges of the bridge portion to thus ordinarily maintain the blades so that a dihedral angle is defined between the scraping edges along the longer sections of the blades. A shaft portion extends from the bridge to enable the device to be attached to a power means, such as defined in the copending application, so that when the blades are set into rotation, they will assume a coplanar relationship along their scraping edges.

Referring now to the drawings, which form a part of this original disclosure:

FIG. l is an exploded perspective view in accordance with the principles of the present invention; and

FIG. 2 is a side elevational view of the scraping blade assembly.

Referring now to FIG. 1, there is shown therein a pair of elongated scraping blade members generally designated 20 and although such scraping blade members are or can be identical to one another. Each scraping blade member includes a lower scraping edge with such edges being designated 22 and 32 respectively an an opposed upper edge designated 24 and 34 respectively. Each of the scraping blade members has an aperture extending transversely therethrough, with the apertures being designated 26 and 36, respectively. The aper tures 26 and 36 are not formed at the center of the blades 20 and 30, but instead, such apertures are offset to one side of the center so that each blade has a longer section to one side of the center of the aperture and a shorter section to the opposite side thereof. That portion of the blade 20 which forms the shorter section thereof to one side of the center of the aperture 26 is designated 208 while the longer section of the blade 20 to the opposite side of the center of the aperture 36 is designated 20L. In a similar manner, the shorter portion of the blade 30 to one side of the center of the aperture 36 is designated 308 while the longer portion to the opposite side of the center of the aperture 36 is designated 30L.

A blade supporting and mounting means generally designated 40 is provided for the purpose of supporting the blades 20 and 30. The means 40 includes a pair of spaced parallel walls 42, which define between them a space 44 which can also be referred to as the blade receiving space. Apertures 46 are formed in the walls 42 with such apertures being aligned with one another along an axis 48 generally perpendicular to the walls 42. The walls 42 are joined together by being integrally formed with a bridge portion 50 in the form of an arch connecting the tops of the walls 42. The bridge portion 50 has side edges 52 along opposite sides thereof which serve a purpose to be defined presently hereinafter. A shaft 54 projects from the top of the bridge portion 50 with the shaft 54 being aligned along an axis perpendicular to the axis 46.

A rod means generally designated is provided to extend along the axis 48, through the apertures 26, 36 and 46 for the purpose of mounting the blades 20 and 30 within the space 44. ln the form shown, the rod member 60 is formed as a bolt having a circular shank 62 within enlarged head 64 at one end thereof and screw threads 66 at the opposite end thereof. A nut 68 mates with the screw thread 66 to maintain the bolt in position.

When the assembly is being put together, the blades 20 and 30 are aligned as shown in FIG. 1, with the apertures 26 and 36 being in alignment with each other. Thus, it can be noted that the longer section 20L of the blade 20 is aligned opposite the shorter section 308 of the blade 30. Similarly, the shorter section 208 of the blade 20 is aligned beside the longer section 30L of the blade 30. With the blades aligned in this manner, they are inserted into the blade receiving space 44 so that apertures 26 and 36 are aligned along the axis 48, which brings such apertures into alignment with the apertures 46 in the walls 42. Then, the threaded shank 62 can be projected through one aperture 46, through the apertures 26 and 36 in the blades and out the other aperture 46 to receive the nut 68. When the nut is tightened onto the threaded portion 66 of the bolt sufficiently to bring the head 64 into contact with one wall 42 and the nut 68 in contact with the opposite wall 42, the assembly will be completed.

The diameter of the blade apertures 26 and 36 is somewhat greater than the cross sectional diameter of the rod 62, thus assuring that the blade members 20 and 30 can rotate relatively to the rod means. Because the weight of the longer sections 201.. and 30L exceeds the weight of the shorter sections, the consequent moment arm tends to tilt the blade members in the manner shown in FIG. 2. Such tilting continues to occur until the upper edge 24 along the shorter section 208 of the blade 20, and the corresponding upper edge 34 along the shorter blade section 305, contacts against the side edges 52 of the bridge portion 50. Such contact prevents further rotation and serves to limit the size of the dihedral angle designated x which is formed between the scraping edges 22 and 32 along the longer sections 20L and 30L of the blades. The size of this dihedral angle x is maintained between about 90 and about 180. When the shaft 54 is attached to a suitable drive means and the assembly is rotated, the blades will swing from their solid line position shown in FIG. 2 to th position shown in phantom lines therein, wherein the scraping edges 22 and 32 are substantially coplanar, which means that the dihedral angle x is substantially 180.

Obviously, the size of the dihedral angle x can be controlled by varying several different factors. One factor can be the width of the bridge portion 50 between the side edges 52 thereof. Another factor can be the placement of the apertures 26 and 36 between the upper edges 24 and 34 and the lower edges 22 and 32 of the blades. Many such variations can be made without departing from the spirit and the scope of the present invention, as defined in the appended claims:

What is claimed is:

1. A scraping blade assembly comprising:

a set of elongated scraping blade members, each of which including a lower scraping edge and an opposed upper edge;

each of said scraping blade members having an aperture extending transversely therethrough;

a blade supporting and mounting means including a pair of spaced walls which define therebetween a blade receiving space;

each of said walls having an aperture extending transversely therethrough;

said pair of scraping blade members being disposed within said blade receiving space, with said apertures through said blade members being aligned with said apertures through said walls; and

a rod member projecting through said apertures in said blade members and said walls to attach said blade members to said blade supporting and mounting means;

said apertures through said blade members being diametrally larger than said rod member to assure that said blade members can rotate relatively to saidrod member.

2. A scraping blade assembly as defined in claim 1 wherein said blade supporting and mounting means further includes a bridge portion interconnecting said pair of spaced walls, said bridge portion having side edges on opposite sides thereof above said blade receiving space.

3. A scraping blade assembly as defined in claim 2 wherein the aperture in said blade members are offset from the midpoints thereof to define a longer section of each blade to one side of the center of said aperture therein and a shorter section of each blade to the other side of the center of said aperture therein.

4. A scraping blade assembly as defined in claim 3 wherein said blade members are disposed in said blade receiving space are positioned with the shorter section of one blade member positioned in juxtaposition to the longer section of the other blade member.

5. A scraping blade assembly as defined in claim 3 wherein said upper edges along each of said shorter sections of said blade members can contact against said side edges of said bridge portion and wherein said scraping edges along each of said longer sections define between them, a dihedral angle.

6. A scraping blade assembly as defined in claim 5 wherein said dihedral angle is between about and about 7. A scraping blade assembly as defined in claim 3 wherein said blade supporting and mounting means further includes a shaft extending from said bridge portion, said shaft being disposed substantially perpendicularly to said rod member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CGRRE'CTION Patent 83 Dated Februarx 12, 1974 Inventor(s) W.

It is certified that error appeafs in the above-identified patent and that said Letters Patent are hereby-corrected as shown below:

On the title page, in the [*1 Notice, at line 2, change Signed and sealed this 14th day of June 197M.-

(SEAL) Attest: r

EDWARD M.FLETCHER,JR. c. MARSHALL 'DANN Attesting Officer Commissioner of Patents FORM 95 uscoMM-oc wave-pee 

1. A scraping blade assembly comprising: a set of elongated scraping blade members, each of which including a lower scraping edge and an opposed upper edge; each of said scraping blade members having an aperture extending transversely therethrough; a blade supporting and mounting means including a pair of spaced walls which define therebetween a blade receiving space; each of said walls having an aperture extending transversely therethrough; said pair of scraping blade members being disposed within said blade receiving space, with said apertures through said blade members being aligned with said apertures through said walls; and a rod member projecting through said apertures in said blade members and said walls to attach said blade members to said blade supporting and mounting means; said apertures through said blade members being diametrally larger than said rod member to assure that said blade members can rotate relatively to said rod member.
 2. A scraping blade assembly as defined in claim 1 wherein said blade supporting and mounting means further includes A bridge portion interconnecting said pair of spaced walls, said bridge portion having side edges on opposite sides thereof above said blade receiving space.
 3. A scraping blade assembly as defined in claim 2 wherein the aperture in said blade members are offset from the midpoints thereof to define a longer section of each blade to one side of the center of said aperture therein and a shorter section of each blade to the other side of the center of said aperture therein.
 4. A scraping blade assembly as defined in claim 3 wherein said blade members are disposed in said blade receiving space are positioned with the shorter section of one blade member positioned in juxtaposition to the longer section of the other blade member.
 5. A scraping blade assembly as defined in claim 3 wherein said upper edges along each of said shorter sections of said blade members can contact against said side edges of said bridge portion and wherein said scraping edges along each of said longer sections define between them, a dihedral angle.
 6. A scraping blade assembly as defined in claim 5 wherein said dihedral angle is between about 90* and about 180*.
 7. A scraping blade assembly as defined in claim 3 wherein said blade supporting and mounting means further includes a shaft extending from said bridge portion, said shaft being disposed substantially perpendicularly to said rod member. 